KSJ-100 is a polyester anti-hydrolysis agent containing special functional groups. It improves the service life of polyester-based polymers, particularly their hydrolytic stability under harsh service conditions such as high temperature and high humidity. The applicable polymers include PLA, PBAT, PBT, PET, PU, etc. KSJ-100 reacts with the decomposition by-products of polyester to form stable compounds that have no adverse effect on the stability of the base material. It also prevents molecular weight reduction of the polymer during processing.